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144 Commits

Author SHA1 Message Date
Austin Clements
d5bd797ee5 runtime: fix getArgInfo for deferred reflection calls
getArgInfo for reflect.makeFuncStub and reflect.methodValueCall is
necessarily special. These have dynamically determined argument maps
that are stored in their context (that is, their *funcval). These
functions are written to store this context at 0(SP) when called, and
getArgInfo retrieves it from there.

This technique works if getArgInfo is passed an active call frame for
one of these functions. However, getArgInfo is also used in
tracebackdefers, where the "call" is not a true call with an active
stack frame, but a deferred call. In this situation, getArgInfo
currently crashes because tracebackdefers passes a frame with sp set
to 0. However, the entire approach used by getArgInfo is flawed in
this situation because the wrapper has not actually executed, and
hence hasn't saved this metadata to any stack frame.

In the defer case, we know the *funcval from the _defer itself, so we
can fix this by teaching getArgInfo to use the *funcval context
directly when its available, and otherwise get it from the active call
frame.

While we're here, this commit simplifies getArgInfo a bit by making it
play more nicely with the type system. Rather than decoding the
*reflect.methodValue that is the wrapper's context as a *[2]uintptr,
just write out a copy of the reflect.methodValue type in the runtime.

Fixes #16331. Fixes #17471.

Change-Id: I81db4d985179b4a81c68c490cceeccbfc675456a
Reviewed-on: https://go-review.googlesource.com/31138
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-10-17 18:57:01 +00:00
Robert Griesemer
ddb77100a6 reflect: ignore struct tags when converting structs
Implementation of spec change https://golang.org/cl/24190/.

For #16085.

Change-Id: Ib7cb513354269282dfad663c7d2c6e624149f3cd
Reviewed-on: https://go-review.googlesource.com/30191
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-10-04 17:15:59 +00:00
Brad Fitzpatrick
ca04091f5b reflect: add Swapper func
Swapper returns a func that swaps two elements in a slice.

Updates #16721

Change-Id: I7f2287a675c10a05019e02b7d62fb870af31216f
Reviewed-on: https://go-review.googlesource.com/30088
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-09-30 20:26:54 +00:00
Michael Munday
3436f0776f reflect, runtime: optimize Value.Call on s390x and add benchmark
Use an MVC loop to copy arguments in runtime.call* rather than copying
bytes individually.

I've added the benchmark CallArgCopy to test the speed of Value.Call
for various argument sizes.

name                    old speed      new speed       delta
CallArgCopy/size=128     439MB/s ± 1%    582MB/s ± 1%   +32.41%  (p=0.000 n=10+10)
CallArgCopy/size=256     695MB/s ± 1%   1172MB/s ± 1%   +68.67%  (p=0.000 n=10+10)
CallArgCopy/size=1024    573MB/s ± 8%   4175MB/s ± 2%  +628.11%  (p=0.000 n=10+10)
CallArgCopy/size=4096   1.46GB/s ± 2%  10.19GB/s ± 1%  +600.52%  (p=0.000 n=10+10)
CallArgCopy/size=65536  1.51GB/s ± 0%  12.30GB/s ± 1%  +716.30%   (p=0.000 n=9+10)

Change-Id: I87dae4809330e7964f6cb4a9e40e5b3254dd519d
Reviewed-on: https://go-review.googlesource.com/28096
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bill O'Farrell <billotosyr@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-27 16:00:19 +00:00
Tormod Erevik Lea
f2f374d125 reflect: update location of vet tool in comment
Change-Id: Ic5160edbbca4a8ffc7c7e6246e34fae1978470fd
Reviewed-on: https://go-review.googlesource.com/28912
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-09 15:02:46 +00:00
Matthew Dempsky
be23e98e06 reflect: cleanup wording for type identity/equality
Use terms like "equal" and "identical types" to match the Go spec,
rather than inventing a new explanation. See also discussion on
golang.org/cl/27170.

Updates #16348.

Change-Id: I0fe0bd01c0d1da3c8937a579c2ba44cf1eb16b71
Reviewed-on: https://go-review.googlesource.com/28054
Reviewed-by: Rob Pike <r@golang.org>
2016-08-30 22:40:52 +00:00
Dave Cheney
adb1e67f02 reflect: avoid zeroing memory that will be overwritten
Avoid new'ing memory that will be overwritten by assignment.

name              old time/op    new time/op    delta
Call-4               160ns ± 4%     155ns ± 2%  -3.19%        (p=0.003 n=10+10)
FieldByName1-4      94.5ns ± 2%    95.2ns ± 1%  +0.65%          (p=0.026 n=9+9)
FieldByName2-4      3.09µs ± 4%    3.13µs ± 2%    ~           (p=0.165 n=10+10)
FieldByName3-4      19.8µs ± 1%    19.9µs ± 1%    ~            (p=0.395 n=10+8)
InterfaceBig-4      11.6ns ± 0%    11.7ns ± 0%  +0.86%          (p=0.000 n=8+9)
InterfaceSmall-4    11.7ns ± 0%    11.7ns ± 0%    ~     (all samples are equal)
New-4               26.6ns ± 0%    26.4ns ± 0%  -0.64%         (p=0.000 n=10+9)

name              old alloc/op   new alloc/op   delta
Call-4              0.00B ±NaN%    0.00B ±NaN%    ~     (all samples are equal)

name              old allocs/op  new allocs/op  delta
Call-4               0.00 ±NaN%     0.00 ±NaN%    ~     (all samples are equal)

Change-Id: I12c85d4e65245598669dd6f66beb0744ec9b9d6d
Reviewed-on: https://go-review.googlesource.com/28011
Run-TryBot: Dave Cheney <dave@cheney.net>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-08-30 08:08:37 +00:00
Ross Light
ec75230b55 reflect: document equality guarantee for Type
The only previous mention of this property was in the String() method.
Since this is the only way to uniquely identify a type and we can't
change this property without breaking the Go 1 guarantee, it seems
better to document this property than hiding it on a method.

Fixes #16348

Change-Id: I3d25f7d6e6007e3c15c2e13010869888d0181fc2
Reviewed-on: https://go-review.googlesource.com/27170
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-08-23 23:20:48 +00:00
David Crawshaw
56752eb2b8 reflect: clear tflag on new types
Fixes #16722

Change-Id: I50a0e69d3e79d13bc1860cd983267c3db087a4b8
Reviewed-on: https://go-review.googlesource.com/27119
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-08-16 16:58:15 +00:00
Ian Lance Taylor
1f4e68d92b reflect: an unnamed type has no PkgPath
The reflect package was returning a non-empty PkgPath for an unnamed
type with methods, such as a type whose methods have a pointer
receiver.

Fixes #16328.

Change-Id: I733e93981ebb5c5c108ef9b03bf5494930b93cf3
Reviewed-on: https://go-review.googlesource.com/24862
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-07-12 12:43:48 +00:00
David Crawshaw
ed9362f769 reflect, runtime: optimize Name method
Several minor changes that remove a good chunk of the overhead added
to the reflect Name method over the 1.7 cycle, as seen from the
non-SSA architectures.

In particular, there are ~20 fewer instructions in reflect.name.name
on 386, and the method now qualifies for inlining.

The simple JSON decoding benchmark on darwin/386:

	name           old time/op    new time/op    delta
	CodeDecoder-8    49.2ms ± 0%    48.9ms ± 1%  -0.77%  (p=0.000 n=10+9)

	name           old speed      new speed      delta
	CodeDecoder-8  39.4MB/s ± 0%  39.7MB/s ± 1%  +0.77%  (p=0.000 n=10+9)

On darwin/amd64 the effect is less pronounced:

	name           old time/op    new time/op    delta
	CodeDecoder-8    38.9ms ± 0%    38.7ms ± 1%  -0.38%  (p=0.005 n=10+10)

	name           old speed      new speed      delta
	CodeDecoder-8  49.9MB/s ± 0%  50.1MB/s ± 1%  +0.38%  (p=0.006 n=10+10)

Counterintuitively, I get much more useful benchmark data out of my
MacBook Pro than a linux workstation with more expensive Intel chips.
While the laptop has fewer cores and an active GUI, the single-threaded
performance is significantly better (nearly 1.5x decoding throughput)
so the differences are more pronounced.

For #16117.

Change-Id: I4e0cc1cc2d271d47d5127b1ee1ca926faf34cabf
Reviewed-on: https://go-review.googlesource.com/24510
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-06-28 12:28:05 +00:00
David Crawshaw
797dc58457 cmd/compile, etc: use tflag to optimize Name()==""
Improves JSON decoding benchmark:

	name                  old time/op    new time/op    delta
	CodeDecoder-8           41.3ms ± 6%    39.8ms ± 1%  -3.61%  (p=0.000 n=10+10)

	name                  old speed      new speed      delta
	CodeDecoder-8         47.0MB/s ± 6%  48.7MB/s ± 1%  +3.66%  (p=0.000 n=10+10)

Change-Id: I524ee05c432fad5252e79b29222ec635c1dee4b4
Reviewed-on: https://go-review.googlesource.com/24452
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-06-24 20:05:34 +00:00
David Crawshaw
3c6ed76da2 reflect: avoid lock for some NumMethod()==0 cases
The encoding/json package uses NumMethod()==0 as a fast check for
interface satisfaction. In the case when a type has no methods at
all, we don't need to grab the RWMutex.

Improves JSON decoding benchmark on linux/amd64:

	name           old time/op    new time/op    delta
	CodeDecoder-8    44.2ms ± 2%    40.6ms ± 1%  -8.11%  (p=0.000 n=10+10)

	name           old speed      new speed      delta
	CodeDecoder-8  43.9MB/s ± 2%  47.8MB/s ± 1%  +8.82%  (p=0.000 n=10+10)

For #16117

Change-Id: Id717e7fcd2f41b7d51d50c26ac167af45bae3747
Reviewed-on: https://go-review.googlesource.com/24433
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-06-24 18:01:08 +00:00
David Crawshaw
e75c899a10 reflect: optimize (reflect.Type).Name
Improves JSON decoding on linux/amd64.

name                   old time/op    new time/op    delta
CodeUnmarshal-40         89.3ms ± 2%    86.3ms ± 2%  -3.31%  (p=0.000 n=22+22)

name                   old speed      new speed      delta
CodeUnmarshal-40       21.7MB/s ± 2%  22.5MB/s ± 2%  +3.44%  (p=0.000 n=22+22)

Updates #16117

Change-Id: I52acf31d7729400cfe6693e46292d41e1addba3d
Reviewed-on: https://go-review.googlesource.com/24410
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-06-23 18:19:52 +00:00
David Crawshaw
e369490fb7 cmd/compile, etc: bring back ptrToThis
This was removed in CL 19695 but it slows down reflect.New, which ends
up on the hot path of things like JSON decoding.

There is no immediate cost in binary size, but it will make it harder to
further shrink run time type information in Go 1.8.

Before

	BenchmarkNew-40         30000000                36.3 ns/op

After

	BenchmarkNew-40         50000000                29.5 ns/op

Fixes #16161
Updates #16117

Change-Id: If7cb7f3e745d44678f3f5cf3a5338c59847529d2
Reviewed-on: https://go-review.googlesource.com/24400
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-06-23 17:39:38 +00:00
David Crawshaw
af0fc83985 cmd/compile, etc: handle many struct fields
This adds 8 bytes of binary size to every type that has methods. It is
the smallest change I could come up with for 1.7.

Fixes #16037

Change-Id: Ibe15c3165854a21768596967757864b880dbfeed
Reviewed-on: https://go-review.googlesource.com/24070
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-06-14 15:32:34 +00:00
David Crawshaw
4b64c53c03 reflect: clear tflag for StructOf type
Fixes #15923

Change-Id: I3e56564365086ceb0bfc15db61db6fb446ab7448
Reviewed-on: https://go-review.googlesource.com/23760
Reviewed-by: Sebastien Binet <seb.binet@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-06-03 19:01:03 +00:00
Sebastien Binet
905ced0e6a reflect: document StructOf embedded fields limitation
This CL documents that StructOf currently does not generate wrapper
methods for embedded fields.

Updates #15924

Change-Id: I932011b1491d68767709559f515f699c04ce70d4
Reviewed-on: https://go-review.googlesource.com/23681
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-06-02 14:29:03 +00:00
David Crawshaw
56e5e0b69c runtime: tell race detector about reflectOffs.lock
Fixes #15832

Change-Id: I6f3f45e3c21edd0e093ecb1d8a067907863478f5
Reviewed-on: https://go-review.googlesource.com/23441
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
2016-05-26 14:43:27 +00:00
David Crawshaw
9f38796270 reflect: remove type info for unexported methods
Also remove some of the now unnecessary corner case handling and
tests I've been adding recently for unexported method data.

For #15673

Change-Id: Ie0c7b03f2370bbe8508cdc5be765028f08000bd7
Reviewed-on: https://go-review.googlesource.com/23410
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-25 12:15:32 +00:00
David Crawshaw
be1b930653 reflect: hide unexported methods that do not satisfy interfaces
Fixes #15673

Change-Id: Ib36d8db3299a93d92665dbde012d52c2c5332ac0
Reviewed-on: https://go-review.googlesource.com/23253
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-20 14:36:14 +00:00
Colin Cross
9d36cac99c reflect: remove out of date UTF-8 StructOf restriction
The initial implementation of reflect.StructOf in
https://golang.org/cl/9251 had a limitation that field names had to be
ASCII, which was later lifted by https://golang.org/cl/21777.  Remove
the out-of-date documentation disallowing UTF-8 field names.

Updates: #5748
Updates: #15064

Change-Id: I2c5bfea46bfd682449c6e847fc972a1a131f51b7
Reviewed-on: https://go-review.googlesource.com/23170
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-05-17 21:15:46 +00:00
David Crawshaw
0cc710dca6 reflect: fix method type string
By picking up a spurious tFlagExtraStar, the method type was printing
as unc instead of func.

Updates #15673

Change-Id: I0c2c189b99bdd4caeb393693be7520b8e3f342bf
Reviewed-on: https://go-review.googlesource.com/23103
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-13 17:44:48 +00:00
Aliaksandr Valialkin
a71584975d reflect: fix vet warnings
Updated #11041

Change-Id: I4a110ba8fefb367a1049b4a65dd20c39eb890ea2
Reviewed-on: https://go-review.googlesource.com/23080
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-12 15:58:28 +00:00
Emmanuel Odeke
9edb27e76f reflect: make Field panic when out of bounds, as documented
Fixes #15046.

Change-Id: Iba7216297735be8e1ec550ce5336d17dcd3fd6b7
Reviewed-on: https://go-review.googlesource.com/22992
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-10 15:16:33 +00:00
Austin Clements
a20fd1f6ba runtime: reclaim scan/dead bit in first word
With the switch to separate mark bitmaps, the scan/dead bit for the
first word of each object is now unused. Reclaim this bit and use it
as a scan/dead bit, just like words three and on. The second word is
still used for checkmark.

This dramatically simplifies heapBitsSetTypeNoScan and hasPointers,
since they no longer need different cases for 1, 2, and 3+ word
objects. They can instead just manipulate the heap bitmap for the
first word and be done with it.

In order to enable this, we change heapBitsSetType and runGCProg to
always set the scan/dead bit to scan for the first word on every code
path. Since these functions only apply to types that have pointers,
there's no need to do this conditionally: it's *always* necessary to
set the scan bit in the first word.

We also change every place that scans an object and checks if there
are more pointers. Rather than only checking morePointers if the word
is >= 2, we now check morePointers if word != 1 (since that's the
checkmark word).

Looking forward, we should probably reclaim the checkmark bit, too,
but that's going to be quite a bit more work.

Tested by setting doubleCheck in heapBitsSetType and running all.bash
on both linux/amd64 and linux/386, and by running GOGC=10 all.bash.

This particularly improves the FmtFprintf* go1 benchmarks, since they
do a large amount of noscan allocation.

name                      old time/op    new time/op    delta
BinaryTree17-12              2.34s ± 1%     2.38s ± 1%  +1.70%  (p=0.000 n=17+19)
Fannkuch11-12                2.09s ± 0%     2.09s ± 1%    ~     (p=0.276 n=17+16)
FmtFprintfEmpty-12          44.9ns ± 2%    44.8ns ± 2%    ~     (p=0.340 n=19+18)
FmtFprintfString-12          127ns ± 0%     125ns ± 0%  -1.57%  (p=0.000 n=16+15)
FmtFprintfInt-12             128ns ± 0%     122ns ± 1%  -4.45%  (p=0.000 n=15+20)
FmtFprintfIntInt-12          207ns ± 1%     193ns ± 0%  -6.55%  (p=0.000 n=19+14)
FmtFprintfPrefixedInt-12     197ns ± 1%     191ns ± 0%  -2.93%  (p=0.000 n=17+18)
FmtFprintfFloat-12           263ns ± 0%     248ns ± 1%  -5.88%  (p=0.000 n=15+19)
FmtManyArgs-12               794ns ± 0%     779ns ± 1%  -1.90%  (p=0.000 n=18+18)
GobDecode-12                7.14ms ± 2%    7.11ms ± 1%    ~     (p=0.072 n=20+20)
GobEncode-12                5.85ms ± 1%    5.82ms ± 1%  -0.49%  (p=0.000 n=20+20)
Gzip-12                      218ms ± 1%     215ms ± 1%  -1.22%  (p=0.000 n=19+19)
Gunzip-12                   36.8ms ± 0%    36.7ms ± 0%  -0.18%  (p=0.006 n=18+20)
HTTPClientServer-12         77.1µs ± 4%    77.1µs ± 3%    ~     (p=0.945 n=19+20)
JSONEncode-12               15.6ms ± 1%    15.9ms ± 1%  +1.68%  (p=0.000 n=18+20)
JSONDecode-12               55.2ms ± 1%    53.6ms ± 1%  -2.93%  (p=0.000 n=17+19)
Mandelbrot200-12            4.05ms ± 1%    4.05ms ± 0%    ~     (p=0.306 n=17+17)
GoParse-12                  3.14ms ± 1%    3.10ms ± 1%  -1.31%  (p=0.000 n=19+18)
RegexpMatchEasy0_32-12      69.3ns ± 1%    70.0ns ± 0%  +0.89%  (p=0.000 n=19+17)
RegexpMatchEasy0_1K-12       237ns ± 1%     236ns ± 0%  -0.62%  (p=0.000 n=19+16)
RegexpMatchEasy1_32-12      69.5ns ± 1%    70.3ns ± 1%  +1.14%  (p=0.000 n=18+17)
RegexpMatchEasy1_1K-12       377ns ± 1%     366ns ± 1%  -3.03%  (p=0.000 n=15+19)
RegexpMatchMedium_32-12      107ns ± 1%     107ns ± 2%    ~     (p=0.318 n=20+19)
RegexpMatchMedium_1K-12     33.8µs ± 3%    33.5µs ± 1%  -1.04%  (p=0.001 n=20+19)
RegexpMatchHard_32-12       1.68µs ± 1%    1.73µs ± 0%  +2.50%  (p=0.000 n=20+18)
RegexpMatchHard_1K-12       50.8µs ± 1%    52.0µs ± 1%  +2.50%  (p=0.000 n=19+18)
Revcomp-12                   381ms ± 1%     385ms ± 1%  +1.00%  (p=0.000 n=17+18)
Template-12                 64.9ms ± 3%    62.6ms ± 1%  -3.55%  (p=0.000 n=19+18)
TimeParse-12                 324ns ± 0%     328ns ± 1%  +1.25%  (p=0.000 n=18+18)
TimeFormat-12                345ns ± 0%     334ns ± 0%  -3.31%  (p=0.000 n=15+17)
[Geo mean]                  52.1µs         51.5µs       -1.00%

Change-Id: I13e74da3193a7f80794c654f944d1f0d60817049
Reviewed-on: https://go-review.googlesource.com/22632
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-30 16:49:54 +00:00
David Crawshaw
bddfc337f9 reflect: fix strings of SliceOf-created types
The new type was inheriting the tflagExtraStar from its prototype.

Fixes #15467

Change-Id: Ic22c2a55cee7580cb59228d52b97e1c0a1e60220
Reviewed-on: https://go-review.googlesource.com/22501
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
2016-04-27 18:07:24 +00:00
David Crawshaw
217be5b35d reflect: unnamed interface types have no name
Fixes #15468

Change-Id: I8723171f87774a98d5e80e7832ebb96dd1fbea74
Reviewed-on: https://go-review.googlesource.com/22524
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
2016-04-27 18:06:20 +00:00
David Crawshaw
96b8f70e22 cmd/link: correctly decode name length
The linker was incorrectly decoding type name lengths, causing
typelinks to be sorted out of order and in cases where the name was
the exact right length, linker panics.

Added a test to the reflect package that causes TestTypelinksSorted
to fail before this CL. It's not the exact failure seen in #15448
but it has the same cause: decodetype_name calculating the wrong
length.

The equivalent decoders in reflect/type.go and runtime/type.go
have the parenthesis in the right place.

Fixes #15448

Change-Id: I33257633d812b7d2091393cb9d6cc8a73e0138c8
Reviewed-on: https://go-review.googlesource.com/22403
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-26 15:55:06 +00:00
David Crawshaw
c165988360 cmd/compile, etc: use nameOff in uncommonType
linux/amd64 PIE:
	cmd/go:  -62KB (0.5%)
	jujud:  -550KB (0.7%)

For #6853.

Change-Id: Ieb67982abce5832e24b997506f0ae7108f747108
Reviewed-on: https://go-review.googlesource.com/22371
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-04-22 13:51:29 +00:00
David Crawshaw
1492e7db05 cmd/compile, etc: use nameOff for rtype string
linux/amd64:
	cmd/go:   -8KB (basically nothing)

linux/amd64 PIE:
	cmd/go: -191KB (1.6%)
	jujud:  -1.5MB (1.9%)

Updates #6853
Fixes #15064

Change-Id: I0adbb95685e28be92e8548741df0e11daa0a9b5f
Reviewed-on: https://go-review.googlesource.com/21777
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-04-22 10:08:05 +00:00
David Crawshaw
2e2df78ae9 reflect: test that method name offset is valid
Bug fix went in CL 21396, this is a matching test.

Fixes #15343

Change-Id: I3670145c7cac45cb4fb3121ffc039cfb7fa7c87a
Reviewed-on: https://go-review.googlesource.com/22171
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-04-18 19:13:36 +00:00
David Crawshaw
95df0c6ab9 cmd/compile, etc: use name offset in method tables
Introduce and start using nameOff for two encoded names. This pair
of changes is best done together because the linker's method decoder
expects the method layouts to match.

Precursor to converting all existing name and *string fields to
nameOff.

linux/amd64:
	cmd/go:  -45KB (0.5%)
	jujud:  -389KB (0.6%)

linux/amd64 PIE:
	cmd/go: -170KB (1.4%)
	jujud:  -1.5MB (1.8%)

For #6853.

Change-Id: Ia044423f010fb987ce070b94c46a16fc78666ff6
Reviewed-on: https://go-review.googlesource.com/21396
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-04-18 09:12:41 +00:00
Matthew Dempsky
0da4dbe232 all: remove unnecessary type conversions
cmd and runtime were handled separately, and I'm intentionally skipped
syscall. This is the rest of the standard library.

CL generated mechanically with github.com/mdempsky/unconvert.

Change-Id: I9e0eff886974dedc37adb93f602064b83e469122
Reviewed-on: https://go-review.googlesource.com/22104
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-15 07:31:45 +00:00
David Crawshaw
f120936dff cmd/compile, etc: use name for type pkgPath
By replacing the *string used to represent pkgPath with a
reflect.name everywhere, the embedded *string for package paths
inside the reflect.name can be replaced by an offset, nameOff.
This reduces the number of pointers in the type information.

This also moves all reflect.name types into the same section, making
it possible to use nameOff more widely in later CLs.

No significant binary size change for normal binaries, but:

linux/amd64 PIE:
	cmd/go: -440KB (3.7%)
	jujud:  -2.6MB (3.2%)

For #6853.

Change-Id: I3890b132a784a1090b1b72b32febfe0bea77eaee
Reviewed-on: https://go-review.googlesource.com/21395
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-04-13 20:48:26 +00:00
David Crawshaw
7d469179e6 cmd/compile, etc: store method tables as offsets
This CL introduces the typeOff type and a lookup method of the same
name that can turn a typeOff offset into an *rtype.

In a typical Go binary (built with buildmode=exe, pie, c-archive, or
c-shared), there is one moduledata and all typeOff values are offsets
relative to firstmoduledata.types. This makes computing the pointer
cheap in typical programs.

With buildmode=shared (and one day, buildmode=plugin) there are
multiple modules whose relative offset is determined at runtime.
We identify a type in the general case by the pair of the original
*rtype that references it and its typeOff value. We determine
the module from the original pointer, and then use the typeOff from
there to compute the final *rtype.

To ensure there is only one *rtype representing each type, the
runtime initializes a typemap for each module, using any identical
type from an earlier module when resolving that offset. This means
that types computed from an offset match the type mapped by the
pointer dynamic relocations.

A series of followup CLs will replace other *rtype values with typeOff
(and name/*string with nameOff).

For types created at runtime by reflect, type offsets are treated as
global IDs and reference into a reflect offset map kept by the runtime.

darwin/amd64:
	cmd/go:  -57KB (0.6%)
	jujud:  -557KB (0.8%)

linux/amd64 PIE:
	cmd/go: -361KB (3.0%)
	jujud:  -3.5MB (4.2%)

For #6853.

Change-Id: Icf096fd884a0a0cb9f280f46f7a26c70a9006c96
Reviewed-on: https://go-review.googlesource.com/21285
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-13 13:03:11 +00:00
Ian Lance Taylor
982274c96d reflect: test that Call results are not addressable
Gccgo was erroneously marking Call results as addressable, which led to
an obscure bug using text/template, as text/template calls CanAddr to
check whether to take the address of a value when looking up methods.
When a function returned a pointer, and CanAddr was true, the result was
a pointer to a pointer that had no methods.

Fixed in gccgo by https://golang.org/cl/21908.  Adding the test here so
that it doesn't regress.

Change-Id: I1d25b868e1b8e2348b21cbac6404a636376d1a4a
Reviewed-on: https://go-review.googlesource.com/21930
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-12 23:14:16 +00:00
David Crawshaw
f028b9f9e2 cmd/link, etc: store typelinks as offsets
This is the first in a series of CLs to replace the use of pointers
in binary read-only data with offsets.

In standard Go binaries these CLs have a small effect, shrinking
8-byte pointers to 4-bytes. In position-independent code, it also
saves the dynamic relocation for the pointer. This has a significant
effect on the binary size when building as PIE, c-archive, or
c-shared.

darwin/amd64:
	cmd/go: -12KB (0.1%)
	jujud:  -82KB (0.1%)

linux/amd64 PIE:
	cmd/go:  -86KB (0.7%)
	jujud:  -569KB (0.7%)

For #6853.

Change-Id: Iad5625bbeba58dabfd4d334dbee3fcbfe04b2dcf
Reviewed-on: https://go-review.googlesource.com/21284
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-12 20:32:41 +00:00
Michael Munday
db9348b866 reflect: add s390x support
Change-Id: I1f975130179cf26af67e82664310b93d43e87a75
Reviewed-on: https://go-review.googlesource.com/20944
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-06 04:23:06 +00:00
Sebastien Binet
633ab7426a reflect: implement StructOf
This change exposes a facility to create new struct types from a slice of
reflect.StructFields.

- reflect: first stab at implementing StructOf
- reflect: tests for StructOf

StructOf creates new struct types in the form of structTypeWithMethods
to accomodate the GC (especially the uncommonType.methods slice field.)

Creating struct types with embedded interfaces with unexported methods
is not supported yet and will panic.
Creating struct types with non-ASCII field names or types is not yet
supported (see #15064.)

Binaries' sizes for linux_amd64:

old=tip (0104a31)

            old bytes     new bytes     delta
bin/go      9911336       9915456       +0.04%
reflect     781704        830048        +6.18%

Updates #5748.
Updates #15064.

Change-Id: I3b8fd4fadd6ce3b1b922e284f0ae72a3a8e3ce44
Reviewed-on: https://go-review.googlesource.com/9251
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
2016-04-01 14:56:21 +00:00
David Crawshaw
43a274fd67 cmd/compile: include pkgPath on all struct types
Fixes #15026.

Change-Id: I61ed71152b99973270d79264d1e8f466f7343c02
Reviewed-on: https://go-review.googlesource.com/21286
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-03-31 20:11:39 +00:00
David Crawshaw
640164bc1c reflect: test name data is aligned
For #14962.

Change-Id: I3539d882487c99dee99ac953e039b79c6b963cf9
Reviewed-on: https://go-review.googlesource.com/21150
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-25 20:37:08 +00:00
David Crawshaw
8cb74e1d18 reflect: name interface type that pins method info
I recently added TestUnexportedMethods which uses an interface type
to pin type information for an unexported method. But as written,
the interface type is not accessible to the reflect package.

You can imagine a future compiler optimization realizing that and
removing the type information for f. In fact, cl/20901 happens to
do that.

Change-Id: I1ddb67f50cb9b5737253b58f10545f3de652c29d
Reviewed-on: https://go-review.googlesource.com/21112
Reviewed-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-25 17:19:03 +00:00
Dominik Honnef
fdba5a7544 all: delete dead non-test code
This change removes a lot of dead code. Some of the code has never been
used, not even when it was first commited. The rest shouldn't have
survived refactors.

This change doesn't remove unused routines helpful for debugging, nor
does it remove code that's used in commented out blocks of code that are
only unused temporarily. Furthermore, unused constants weren't removed
when they were part of a set of constants from specifications.

One noteworthy omission from this CL are about 1000 lines of unused code
in cmd/fix, 700 lines of which are the typechecker, which hasn't been
used ever since the pre-Go 1 fixes have been removed. I wasn't sure if
this code should stick around for future uses of cmd/fix or be culled as
well.

Change-Id: Ib714bc7e487edc11ad23ba1c3222d1fd02e4a549
Reviewed-on: https://go-review.googlesource.com/20926
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-25 06:28:13 +00:00
John Jeffery
5c8674a497 reflect: add method StructTag.Lookup
The Lookup method provides a way to extract a tag value, while
determining whether the tag key exists in the struct field's tag.

Fixes #14883

Change-Id: I7460cb68f0ca1aaa025935050b9e182efcb64db3
Reviewed-on: https://go-review.googlesource.com/20864
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-25 04:54:19 +00:00
David Crawshaw
24ce64d1a9 cmd/compile, runtime: new static name encoding
Create a byte encoding designed for static Go names.

It is intended to be a compact representation of a name
and optional tag data that can be turned into a Go string
without allocating, and describes whether or not it is
exported without unicode table.

The encoding is described in reflect/type.go:

// The first byte is a bit field containing:
//
//	1<<0 the name is exported
//	1<<1 tag data follows the name
//	1<<2 pkgPath *string follow the name and tag
//
// The next two bytes are the data length:
//
//	 l := uint16(data[1])<<8 | uint16(data[2])
//
// Bytes [3:3+l] are the string data.
//
// If tag data follows then bytes 3+l and 3+l+1 are the tag length,
// with the data following.
//
// If the import path follows, then ptrSize bytes at the end of
// the data form a *string. The import path is only set for concrete
// methods that are defined in a different package than their type.

Shrinks binary sizes:

	cmd/go: 164KB (1.6%)
	jujud:  1.0MB (1.5%)

For #6853.

Change-Id: I46b6591015b17936a443c9efb5009de8dfe8b609
Reviewed-on: https://go-review.googlesource.com/20968
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-03-25 00:13:49 +00:00
David Crawshaw
44d3f89e99 cmd/link, reflect: remove some method type data
Remove reflect type information for unexported methods that do not
satisfy any interface in the program.

Ideally the unexported method would not appear in the method list at
all, but that is tricky because the slice is built by the compiler.

Reduces binary size:

	cmd/go: 81KB (0.8%)
	jujud: 258KB (0.4%)

For #6853.

Change-Id: I25ef8df6907e9ac03b18689d584ea46e7d773043
Reviewed-on: https://go-review.googlesource.com/21033
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-23 17:00:43 +00:00
Dominik Honnef
b2cf571040 all: delete dead test code
This deletes unused code and helpers from tests.

Change-Id: Ie31d46115f558ceb8da6efbf90c3c204e03b0d7e
Reviewed-on: https://go-review.googlesource.com/20927
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-21 07:10:08 +00:00
David Crawshaw
f2772a4935 cmd/compile: compute second method type at runtime
The type information for a method includes two variants: a func
without the receiver, and a func with the receiver as the first
parameter. The former is used as part of the dynamic interface
checks, but the latter is only returned as a type in the
reflect.Method struct.

Instead of computing it at compile time, construct it at run time
with reflect.FuncOf.

Using cl/20701 as a baseline,

	cmd/go: -480KB, (4.4%)
	jujud:  -5.6MB, (7.8%)

For #6853.

Change-Id: I1b8c73f3ab894735f53d00cb9c0b506d84d54e92
Reviewed-on: https://go-review.googlesource.com/20709
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-03-15 19:57:40 +00:00
Dominik Honnef
368507bb6f reflect: use SelectDir instead of uintptr in runtimeSelect
And fix the wrong comment.

Initially found this because the comment was wrong about the possible
values. Then noticed that there doesn't seem to be any reason to use
uintptr over SelectDir.

Change-Id: I4f9f9640e49d89e558ed00bd99e57dab890785f5
Reviewed-on: https://go-review.googlesource.com/20655
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-14 01:55:31 +00:00